--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * This driver adds support for perf events to use the Performance
+ * Monitor Counter Groups (PMCG) associated with an SMMUv3 node
+ * to monitor that node.
+ *
+ * SMMUv3 PMCG devices are named as smmuv3_pmcg_<phys_addr_page> where
+ * <phys_addr_page> is the physical page address of the SMMU PMCG wrapped
+ * to 4K boundary. For example, the PMCG at 0xff88840000 is named
+ * smmuv3_pmcg_ff88840
+ *
+ * Filtering by stream id is done by specifying filtering parameters
+ * with the event. options are:
+ *   filter_enable    - 0 = no filtering, 1 = filtering enabled
+ *   filter_span      - 0 = exact match, 1 = pattern match
+ *   filter_stream_id - pattern to filter against
+ *
+ * To match a partial StreamID where the X most-significant bits must match
+ * but the Y least-significant bits might differ, STREAMID is programmed
+ * with a value that contains:
+ *  STREAMID[Y - 1] == 0.
+ *  STREAMID[Y - 2:0] == 1 (where Y > 1).
+ * The remainder of implemented bits of STREAMID (X bits, from bit Y upwards)
+ * contain a value to match from the corresponding bits of event StreamID.
+ *
+ * Example: perf stat -e smmuv3_pmcg_ff88840/transaction,filter_enable=1,
+ *                    filter_span=1,filter_stream_id=0x42/ -a netperf
+ * Applies filter pattern 0x42 to transaction events, which means events
+ * matching stream ids 0x42 and 0x43 are counted. Further filtering
+ * information is available in the SMMU documentation.
+ *
+ * SMMU events are not attributable to a CPU, so task mode and sampling
+ * are not supported.
+ */
+
+#include <linux/acpi.h>
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/cpuhotplug.h>
+#include <linux/cpumask.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/msi.h>
+#include <linux/perf_event.h>
+#include <linux/platform_device.h>
+#include <linux/smp.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+
+#define SMMU_PMCG_EVCNTR0               0x0
+#define SMMU_PMCG_EVCNTR(n, stride)     (SMMU_PMCG_EVCNTR0 + (n) * (stride))
+#define SMMU_PMCG_EVTYPER0              0x400
+#define SMMU_PMCG_EVTYPER(n)            (SMMU_PMCG_EVTYPER0 + (n) * 4)
+#define SMMU_PMCG_SID_SPAN_SHIFT        29
+#define SMMU_PMCG_SMR0                  0xA00
+#define SMMU_PMCG_SMR(n)                (SMMU_PMCG_SMR0 + (n) * 4)
+#define SMMU_PMCG_CNTENSET0             0xC00
+#define SMMU_PMCG_CNTENCLR0             0xC20
+#define SMMU_PMCG_INTENSET0             0xC40
+#define SMMU_PMCG_INTENCLR0             0xC60
+#define SMMU_PMCG_OVSCLR0               0xC80
+#define SMMU_PMCG_OVSSET0               0xCC0
+#define SMMU_PMCG_CFGR                  0xE00
+#define SMMU_PMCG_CFGR_SID_FILTER_TYPE  BIT(23)
+#define SMMU_PMCG_CFGR_RELOC_CTRS       BIT(20)
+#define SMMU_PMCG_CFGR_SIZE             GENMASK(13, 8)
+#define SMMU_PMCG_CFGR_NCTR             GENMASK(5, 0)
+#define SMMU_PMCG_CR                    0xE04
+#define SMMU_PMCG_CR_ENABLE             BIT(0)
+#define SMMU_PMCG_CEID0                 0xE20
+#define SMMU_PMCG_CEID1                 0xE28
+#define SMMU_PMCG_IRQ_CTRL              0xE50
+#define SMMU_PMCG_IRQ_CTRL_IRQEN        BIT(0)
+#define SMMU_PMCG_IRQ_CFG0              0xE58
+
+#define SMMU_PMCG_DEFAULT_FILTER_SPAN   1
+#define SMMU_PMCG_DEFAULT_FILTER_SID    GENMASK(31, 0)
+
+#define SMMU_PMCG_MAX_COUNTERS          64
+#define SMMU_PMCG_ARCH_MAX_EVENTS       128
+
+#define SMMU_PMCG_PA_SHIFT              12
+
+static int cpuhp_state_num;
+
+struct smmu_pmu {
+       struct hlist_node node;
+       struct perf_event *events[SMMU_PMCG_MAX_COUNTERS];
+       DECLARE_BITMAP(used_counters, SMMU_PMCG_MAX_COUNTERS);
+       DECLARE_BITMAP(supported_events, SMMU_PMCG_ARCH_MAX_EVENTS);
+       unsigned int irq;
+       unsigned int on_cpu;
+       struct pmu pmu;
+       unsigned int num_counters;
+       struct device *dev;
+       void __iomem *reg_base;
+       void __iomem *reloc_base;
+       u64 counter_mask;
+       bool global_filter;
+       u32 global_filter_span;
+       u32 global_filter_sid;
+};
+
+#define to_smmu_pmu(p) (container_of(p, struct smmu_pmu, pmu))
+
+#define SMMU_PMU_EVENT_ATTR_EXTRACTOR(_name, _config, _start, _end)        \
+       static inline u32 get_##_name(struct perf_event *event)            \
+       {                                                                  \
+               return FIELD_GET(GENMASK_ULL(_end, _start),                \
+                                event->attr._config);                     \
+       }                                                                  \
+
+SMMU_PMU_EVENT_ATTR_EXTRACTOR(event, config, 0, 15);
+SMMU_PMU_EVENT_ATTR_EXTRACTOR(filter_stream_id, config1, 0, 31);
+SMMU_PMU_EVENT_ATTR_EXTRACTOR(filter_span, config1, 32, 32);
+SMMU_PMU_EVENT_ATTR_EXTRACTOR(filter_enable, config1, 33, 33);
+
+static inline void smmu_pmu_enable(struct pmu *pmu)
+{
+       struct smmu_pmu *smmu_pmu = to_smmu_pmu(pmu);
+
+       writel(SMMU_PMCG_IRQ_CTRL_IRQEN,
+              smmu_pmu->reg_base + SMMU_PMCG_IRQ_CTRL);
+       writel(SMMU_PMCG_CR_ENABLE, smmu_pmu->reg_base + SMMU_PMCG_CR);
+}
+
+static inline void smmu_pmu_disable(struct pmu *pmu)
+{
+       struct smmu_pmu *smmu_pmu = to_smmu_pmu(pmu);
+
+       writel(0, smmu_pmu->reg_base + SMMU_PMCG_CR);
+       writel(0, smmu_pmu->reg_base + SMMU_PMCG_IRQ_CTRL);
+}
+
+static inline void smmu_pmu_counter_set_value(struct smmu_pmu *smmu_pmu,
+                                             u32 idx, u64 value)
+{
+       if (smmu_pmu->counter_mask & BIT(32))
+               writeq(value, smmu_pmu->reloc_base + SMMU_PMCG_EVCNTR(idx, 8));
+       else
+               writel(value, smmu_pmu->reloc_base + SMMU_PMCG_EVCNTR(idx, 4));
+}
+
+static inline u64 smmu_pmu_counter_get_value(struct smmu_pmu *smmu_pmu, u32 idx)
+{
+       u64 value;
+
+       if (smmu_pmu->counter_mask & BIT(32))
+               value = readq(smmu_pmu->reloc_base + SMMU_PMCG_EVCNTR(idx, 8));
+       else
+               value = readl(smmu_pmu->reloc_base + SMMU_PMCG_EVCNTR(idx, 4));
+
+       return value;
+}
+
+static inline void smmu_pmu_counter_enable(struct smmu_pmu *smmu_pmu, u32 idx)
+{
+       writeq(BIT(idx), smmu_pmu->reg_base + SMMU_PMCG_CNTENSET0);
+}
+
+static inline void smmu_pmu_counter_disable(struct smmu_pmu *smmu_pmu, u32 idx)
+{
+       writeq(BIT(idx), smmu_pmu->reg_base + SMMU_PMCG_CNTENCLR0);
+}
+
+static inline void smmu_pmu_interrupt_enable(struct smmu_pmu *smmu_pmu, u32 idx)
+{
+       writeq(BIT(idx), smmu_pmu->reg_base + SMMU_PMCG_INTENSET0);
+}
+
+static inline void smmu_pmu_interrupt_disable(struct smmu_pmu *smmu_pmu,
+                                             u32 idx)
+{
+       writeq(BIT(idx), smmu_pmu->reg_base + SMMU_PMCG_INTENCLR0);
+}
+
+static inline void smmu_pmu_set_evtyper(struct smmu_pmu *smmu_pmu, u32 idx,
+                                       u32 val)
+{
+       writel(val, smmu_pmu->reg_base + SMMU_PMCG_EVTYPER(idx));
+}
+
+static inline void smmu_pmu_set_smr(struct smmu_pmu *smmu_pmu, u32 idx, u32 val)
+{
+       writel(val, smmu_pmu->reg_base + SMMU_PMCG_SMR(idx));
+}
+
+static void smmu_pmu_event_update(struct perf_event *event)
+{
+       struct hw_perf_event *hwc = &event->hw;
+       struct smmu_pmu *smmu_pmu = to_smmu_pmu(event->pmu);
+       u64 delta, prev, now;
+       u32 idx = hwc->idx;
+
+       do {
+               prev = local64_read(&hwc->prev_count);
+               now = smmu_pmu_counter_get_value(smmu_pmu, idx);
+       } while (local64_cmpxchg(&hwc->prev_count, prev, now) != prev);
+
+       /* handle overflow. */
+       delta = now - prev;
+       delta &= smmu_pmu->counter_mask;
+
+       local64_add(delta, &event->count);
+}
+
+static void smmu_pmu_set_period(struct smmu_pmu *smmu_pmu,
+                               struct hw_perf_event *hwc)
+{
+       u32 idx = hwc->idx;
+       u64 new;
+
+       /*
+        * We limit the max period to half the max counter value of the counter
+        * size, so that even in the case of extreme interrupt latency the
+        * counter will (hopefully) not wrap past its initial value.
+        */
+       new = smmu_pmu->counter_mask >> 1;
+
+       local64_set(&hwc->prev_count, new);
+       smmu_pmu_counter_set_value(smmu_pmu, idx, new);
+}
+
+static void smmu_pmu_set_event_filter(struct perf_event *event,
+                                     int idx, u32 span, u32 sid)
+{
+       struct smmu_pmu *smmu_pmu = to_smmu_pmu(event->pmu);
+       u32 evtyper;
+
+       evtyper = get_event(event) | span << SMMU_PMCG_SID_SPAN_SHIFT;
+       smmu_pmu_set_evtyper(smmu_pmu, idx, evtyper);
+       smmu_pmu_set_smr(smmu_pmu, idx, sid);
+}
+
+static int smmu_pmu_apply_event_filter(struct smmu_pmu *smmu_pmu,
+                                      struct perf_event *event, int idx)
+{
+       u32 span, sid;
+       unsigned int num_ctrs = smmu_pmu->num_counters;
+       bool filter_en = !!get_filter_enable(event);
+
+       span = filter_en ? get_filter_span(event) :
+                          SMMU_PMCG_DEFAULT_FILTER_SPAN;
+       sid = filter_en ? get_filter_stream_id(event) :
+                          SMMU_PMCG_DEFAULT_FILTER_SID;
+
+       /* Support individual filter settings */
+       if (!smmu_pmu->global_filter) {
+               smmu_pmu_set_event_filter(event, idx, span, sid);
+               return 0;
+       }
+
+       /* Requested settings same as current global settings*/
+       if (span == smmu_pmu->global_filter_span &&
+           sid == smmu_pmu->global_filter_sid)
+               return 0;
+
+       if (!bitmap_empty(smmu_pmu->used_counters, num_ctrs))
+               return -EAGAIN;
+
+       smmu_pmu_set_event_filter(event, 0, span, sid);
+       smmu_pmu->global_filter_span = span;
+       smmu_pmu->global_filter_sid = sid;
+       return 0;
+}
+
+static int smmu_pmu_get_event_idx(struct smmu_pmu *smmu_pmu,
+                                 struct perf_event *event)
+{
+       int idx, err;
+       unsigned int num_ctrs = smmu_pmu->num_counters;
+
+       idx = find_first_zero_bit(smmu_pmu->used_counters, num_ctrs);
+       if (idx == num_ctrs)
+               /* The counters are all in use. */
+               return -EAGAIN;
+
+       err = smmu_pmu_apply_event_filter(smmu_pmu, event, idx);
+       if (err)
+               return err;
+
+       set_bit(idx, smmu_pmu->used_counters);
+
+       return idx;
+}
+
+/*
+ * Implementation of abstract pmu functionality required by
+ * the core perf events code.
+ */
+
+static int smmu_pmu_event_init(struct perf_event *event)
+{
+       struct hw_perf_event *hwc = &event->hw;
+       struct smmu_pmu *smmu_pmu = to_smmu_pmu(event->pmu);
+       struct device *dev = smmu_pmu->dev;
+       struct perf_event *sibling;
+       u16 event_id;
+
+       if (event->attr.type != event->pmu->type)
+               return -ENOENT;
+
+       if (hwc->sample_period) {
+               dev_dbg(dev, "Sampling not supported\n");
+               return -EOPNOTSUPP;
+       }
+
+       if (event->cpu < 0) {
+               dev_dbg(dev, "Per-task mode not supported\n");
+               return -EOPNOTSUPP;
+       }
+
+       /* Verify specified event is supported on this PMU */
+       event_id = get_event(event);
+       if (event_id < SMMU_PMCG_ARCH_MAX_EVENTS &&
+           (!test_bit(event_id, smmu_pmu->supported_events))) {
+               dev_dbg(dev, "Invalid event %d for this PMU\n", event_id);
+               return -EINVAL;
+       }
+
+       /* Don't allow groups with mixed PMUs, except for s/w events */
+       if (event->group_leader->pmu != event->pmu &&
+           !is_software_event(event->group_leader)) {
+               dev_dbg(dev, "Can't create mixed PMU group\n");
+               return -EINVAL;
+       }
+
+       for_each_sibling_event(sibling, event->group_leader) {
+               if (sibling->pmu != event->pmu &&
+                   !is_software_event(sibling)) {
+                       dev_dbg(dev, "Can't create mixed PMU group\n");
+                       return -EINVAL;
+               }
+       }
+
+       hwc->idx = -1;
+
+       /*
+        * Ensure all events are on the same cpu so all events are in the
+        * same cpu context, to avoid races on pmu_enable etc.
+        */
+       event->cpu = smmu_pmu->on_cpu;
+
+       return 0;
+}
+
+static void smmu_pmu_event_start(struct perf_event *event, int flags)
+{
+       struct smmu_pmu *smmu_pmu = to_smmu_pmu(event->pmu);
+       struct hw_perf_event *hwc = &event->hw;
+       int idx = hwc->idx;
+
+       hwc->state = 0;
+
+       smmu_pmu_set_period(smmu_pmu, hwc);
+
+       smmu_pmu_counter_enable(smmu_pmu, idx);
+}
+
+static void smmu_pmu_event_stop(struct perf_event *event, int flags)
+{
+       struct smmu_pmu *smmu_pmu = to_smmu_pmu(event->pmu);
+       struct hw_perf_event *hwc = &event->hw;
+       int idx = hwc->idx;
+
+       if (hwc->state & PERF_HES_STOPPED)
+               return;
+
+       smmu_pmu_counter_disable(smmu_pmu, idx);
+       /* As the counter gets updated on _start, ignore PERF_EF_UPDATE */
+       smmu_pmu_event_update(event);
+       hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
+}
+
+static int smmu_pmu_event_add(struct perf_event *event, int flags)
+{
+       struct hw_perf_event *hwc = &event->hw;
+       int idx;
+       struct smmu_pmu *smmu_pmu = to_smmu_pmu(event->pmu);
+
+       idx = smmu_pmu_get_event_idx(smmu_pmu, event);
+       if (idx < 0)
+               return idx;
+
+       hwc->idx = idx;
+       hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
+       smmu_pmu->events[idx] = event;
+       local64_set(&hwc->prev_count, 0);
+
+       smmu_pmu_interrupt_enable(smmu_pmu, idx);
+
+       if (flags & PERF_EF_START)
+               smmu_pmu_event_start(event, flags);
+
+       /* Propagate changes to the userspace mapping. */
+       perf_event_update_userpage(event);
+
+       return 0;
+}
+
+static void smmu_pmu_event_del(struct perf_event *event, int flags)
+{
+       struct hw_perf_event *hwc = &event->hw;
+       struct smmu_pmu *smmu_pmu = to_smmu_pmu(event->pmu);
+       int idx = hwc->idx;
+
+       smmu_pmu_event_stop(event, flags | PERF_EF_UPDATE);
+       smmu_pmu_interrupt_disable(smmu_pmu, idx);
+       smmu_pmu->events[idx] = NULL;
+       clear_bit(idx, smmu_pmu->used_counters);
+
+       perf_event_update_userpage(event);
+}
+
+static void smmu_pmu_event_read(struct perf_event *event)
+{
+       smmu_pmu_event_update(event);
+}
+
+/* cpumask */
+
+static ssize_t smmu_pmu_cpumask_show(struct device *dev,
+                                    struct device_attribute *attr,
+                                    char *buf)
+{
+       struct smmu_pmu *smmu_pmu = to_smmu_pmu(dev_get_drvdata(dev));
+
+       return cpumap_print_to_pagebuf(true, buf, cpumask_of(smmu_pmu->on_cpu));
+}
+
+static struct device_attribute smmu_pmu_cpumask_attr =
+               __ATTR(cpumask, 0444, smmu_pmu_cpumask_show, NULL);
+
+static struct attribute *smmu_pmu_cpumask_attrs[] = {
+       &smmu_pmu_cpumask_attr.attr,
+       NULL
+};
+
+static struct attribute_group smmu_pmu_cpumask_group = {
+       .attrs = smmu_pmu_cpumask_attrs,
+};
+
+/* Events */
+
+static ssize_t smmu_pmu_event_show(struct device *dev,
+                                  struct device_attribute *attr, char *page)
+{
+       struct perf_pmu_events_attr *pmu_attr;
+
+       pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
+
+       return sprintf(page, "event=0x%02llx\n", pmu_attr->id);
+}
+
+#define SMMU_EVENT_ATTR(name, config) \
+       PMU_EVENT_ATTR(name, smmu_event_attr_##name, \
+                      config, smmu_pmu_event_show)
+SMMU_EVENT_ATTR(cycles, 0);
+SMMU_EVENT_ATTR(transaction, 1);
+SMMU_EVENT_ATTR(tlb_miss, 2);
+SMMU_EVENT_ATTR(config_cache_miss, 3);
+SMMU_EVENT_ATTR(trans_table_walk_access, 4);
+SMMU_EVENT_ATTR(config_struct_access, 5);
+SMMU_EVENT_ATTR(pcie_ats_trans_rq, 6);
+SMMU_EVENT_ATTR(pcie_ats_trans_passed, 7);
+
+static struct attribute *smmu_pmu_events[] = {
+       &smmu_event_attr_cycles.attr.attr,
+       &smmu_event_attr_transaction.attr.attr,
+       &smmu_event_attr_tlb_miss.attr.attr,
+       &smmu_event_attr_config_cache_miss.attr.attr,
+       &smmu_event_attr_trans_table_walk_access.attr.attr,
+       &smmu_event_attr_config_struct_access.attr.attr,
+       &smmu_event_attr_pcie_ats_trans_rq.attr.attr,
+       &smmu_event_attr_pcie_ats_trans_passed.attr.attr,
+       NULL
+};
+
+static umode_t smmu_pmu_event_is_visible(struct kobject *kobj,
+                                        struct attribute *attr, int unused)
+{
+       struct device *dev = kobj_to_dev(kobj);
+       struct smmu_pmu *smmu_pmu = to_smmu_pmu(dev_get_drvdata(dev));
+       struct perf_pmu_events_attr *pmu_attr;
+
+       pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr.attr);
+
+       if (test_bit(pmu_attr->id, smmu_pmu->supported_events))
+               return attr->mode;
+
+       return 0;
+}
+
+static struct attribute_group smmu_pmu_events_group = {
+       .name = "events",
+       .attrs = smmu_pmu_events,
+       .is_visible = smmu_pmu_event_is_visible,
+};
+
+/* Formats */
+PMU_FORMAT_ATTR(event,            "config:0-15");
+PMU_FORMAT_ATTR(filter_stream_id,  "config1:0-31");
+PMU_FORMAT_ATTR(filter_span,      "config1:32");
+PMU_FORMAT_ATTR(filter_enable,    "config1:33");
+
+static struct attribute *smmu_pmu_formats[] = {
+       &format_attr_event.attr,
+       &format_attr_filter_stream_id.attr,
+       &format_attr_filter_span.attr,
+       &format_attr_filter_enable.attr,
+       NULL
+};
+
+static struct attribute_group smmu_pmu_format_group = {
+       .name = "format",
+       .attrs = smmu_pmu_formats,
+};
+
+static const struct attribute_group *smmu_pmu_attr_grps[] = {
+       &smmu_pmu_cpumask_group,
+       &smmu_pmu_events_group,
+       &smmu_pmu_format_group,
+       NULL
+};
+
+/*
+ * Generic device handlers
+ */
+
+static int smmu_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
+{
+       struct smmu_pmu *smmu_pmu;
+       unsigned int target;
+
+       smmu_pmu = hlist_entry_safe(node, struct smmu_pmu, node);
+       if (cpu != smmu_pmu->on_cpu)
+               return 0;
+
+       target = cpumask_any_but(cpu_online_mask, cpu);
+       if (target >= nr_cpu_ids)
+               return 0;
+
+       perf_pmu_migrate_context(&smmu_pmu->pmu, cpu, target);
+       smmu_pmu->on_cpu = target;
+       WARN_ON(irq_set_affinity_hint(smmu_pmu->irq, cpumask_of(target)));
+
+       return 0;
+}
+
+static irqreturn_t smmu_pmu_handle_irq(int irq_num, void *data)
+{
+       struct smmu_pmu *smmu_pmu = data;
+       u64 ovsr;
+       unsigned int idx;
+
+       ovsr = readq(smmu_pmu->reloc_base + SMMU_PMCG_OVSSET0);
+       if (!ovsr)
+               return IRQ_NONE;
+
+       writeq(ovsr, smmu_pmu->reloc_base + SMMU_PMCG_OVSCLR0);
+
+       for_each_set_bit(idx, (unsigned long *)&ovsr, smmu_pmu->num_counters) {
+               struct perf_event *event = smmu_pmu->events[idx];
+               struct hw_perf_event *hwc;
+
+               if (WARN_ON_ONCE(!event))
+                       continue;
+
+               smmu_pmu_event_update(event);
+               hwc = &event->hw;
+
+               smmu_pmu_set_period(smmu_pmu, hwc);
+       }
+
+       return IRQ_HANDLED;
+}
+
+static int smmu_pmu_setup_irq(struct smmu_pmu *pmu)
+{
+       unsigned long flags = IRQF_NOBALANCING | IRQF_SHARED | IRQF_NO_THREAD;
+       int irq, ret = -ENXIO;
+
+       irq = pmu->irq;
+       if (irq)
+               ret = devm_request_irq(pmu->dev, irq, smmu_pmu_handle_irq,
+                                      flags, "smmuv3-pmu", pmu);
+       return ret;
+}
+
+static void smmu_pmu_reset(struct smmu_pmu *smmu_pmu)
+{
+       u64 counter_present_mask = GENMASK_ULL(smmu_pmu->num_counters - 1, 0);
+
+       smmu_pmu_disable(&smmu_pmu->pmu);
+
+       /* Disable counter and interrupt */
+       writeq_relaxed(counter_present_mask,
+                      smmu_pmu->reg_base + SMMU_PMCG_CNTENCLR0);
+       writeq_relaxed(counter_present_mask,
+                      smmu_pmu->reg_base + SMMU_PMCG_INTENCLR0);
+       writeq_relaxed(counter_present_mask,
+                      smmu_pmu->reloc_base + SMMU_PMCG_OVSCLR0);
+}
+
+static int smmu_pmu_probe(struct platform_device *pdev)
+{
+       struct smmu_pmu *smmu_pmu;
+       struct resource *res_0, *res_1;
+       u32 cfgr, reg_size;
+       u64 ceid_64[2];
+       int irq, err;
+       char *name;
+       struct device *dev = &pdev->dev;
+
+       smmu_pmu = devm_kzalloc(dev, sizeof(*smmu_pmu), GFP_KERNEL);
+       if (!smmu_pmu)
+               return -ENOMEM;
+
+       smmu_pmu->dev = dev;
+       platform_set_drvdata(pdev, smmu_pmu);
+
+       smmu_pmu->pmu = (struct pmu) {
+               .task_ctx_nr    = perf_invalid_context,
+               .pmu_enable     = smmu_pmu_enable,
+               .pmu_disable    = smmu_pmu_disable,
+               .event_init     = smmu_pmu_event_init,
+               .add            = smmu_pmu_event_add,
+               .del            = smmu_pmu_event_del,
+               .start          = smmu_pmu_event_start,
+               .stop           = smmu_pmu_event_stop,
+               .read           = smmu_pmu_event_read,
+               .attr_groups    = smmu_pmu_attr_grps,
+               .capabilities   = PERF_PMU_CAP_NO_EXCLUDE,
+       };
+
+       res_0 = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       smmu_pmu->reg_base = devm_ioremap_resource(dev, res_0);
+       if (IS_ERR(smmu_pmu->reg_base))
+               return PTR_ERR(smmu_pmu->reg_base);
+
+       cfgr = readl_relaxed(smmu_pmu->reg_base + SMMU_PMCG_CFGR);
+
+       /* Determine if page 1 is present */
+       if (cfgr & SMMU_PMCG_CFGR_RELOC_CTRS) {
+               res_1 = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+               smmu_pmu->reloc_base = devm_ioremap_resource(dev, res_1);
+               if (IS_ERR(smmu_pmu->reloc_base))
+                       return PTR_ERR(smmu_pmu->reloc_base);
+       } else {
+               smmu_pmu->reloc_base = smmu_pmu->reg_base;
+       }
+
+       irq = platform_get_irq(pdev, 0);
+       if (irq > 0)
+               smmu_pmu->irq = irq;
+
+       ceid_64[0] = readq_relaxed(smmu_pmu->reg_base + SMMU_PMCG_CEID0);
+       ceid_64[1] = readq_relaxed(smmu_pmu->reg_base + SMMU_PMCG_CEID1);
+       bitmap_from_arr32(smmu_pmu->supported_events, (u32 *)ceid_64,
+                         SMMU_PMCG_ARCH_MAX_EVENTS);
+
+       smmu_pmu->num_counters = FIELD_GET(SMMU_PMCG_CFGR_NCTR, cfgr) + 1;
+
+       smmu_pmu->global_filter = !!(cfgr & SMMU_PMCG_CFGR_SID_FILTER_TYPE);
+
+       reg_size = FIELD_GET(SMMU_PMCG_CFGR_SIZE, cfgr);
+       smmu_pmu->counter_mask = GENMASK_ULL(reg_size, 0);
+
+       smmu_pmu_reset(smmu_pmu);
+
+       err = smmu_pmu_setup_irq(smmu_pmu);
+       if (err) {
+               dev_err(dev, "Setup irq failed, PMU @%pa\n", &res_0->start);
+               return err;
+       }
+
+       name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "smmuv3_pmcg_%llx",
+                             (res_0->start) >> SMMU_PMCG_PA_SHIFT);
+       if (!name) {
+               dev_err(dev, "Create name failed, PMU @%pa\n", &res_0->start);
+               return -EINVAL;
+       }
+
+       /* Pick one CPU to be the preferred one to use */
+       smmu_pmu->on_cpu = raw_smp_processor_id();
+       WARN_ON(irq_set_affinity_hint(smmu_pmu->irq,
+                                     cpumask_of(smmu_pmu->on_cpu)));
+
+       err = cpuhp_state_add_instance_nocalls(cpuhp_state_num,
+                                              &smmu_pmu->node);
+       if (err) {
+               dev_err(dev, "Error %d registering hotplug, PMU @%pa\n",
+                       err, &res_0->start);
+               goto out_cpuhp_err;
+       }
+
+       err = perf_pmu_register(&smmu_pmu->pmu, name, -1);
+       if (err) {
+               dev_err(dev, "Error %d registering PMU @%pa\n",
+                       err, &res_0->start);
+               goto out_unregister;
+       }
+
+       dev_info(dev, "Registered PMU @ %pa using %d counters with %s filter settings\n",
+                &res_0->start, smmu_pmu->num_counters,
+                smmu_pmu->global_filter ? "Global(Counter0)" :
+                "Individual");
+
+       return 0;
+
+out_unregister:
+       cpuhp_state_remove_instance_nocalls(cpuhp_state_num, &smmu_pmu->node);
+out_cpuhp_err:
+       put_cpu();
+       return err;
+}
+
+static int smmu_pmu_remove(struct platform_device *pdev)
+{
+       struct smmu_pmu *smmu_pmu = platform_get_drvdata(pdev);
+
+       perf_pmu_unregister(&smmu_pmu->pmu);
+       cpuhp_state_remove_instance_nocalls(cpuhp_state_num, &smmu_pmu->node);
+
+       return 0;
+}
+
+static void smmu_pmu_shutdown(struct platform_device *pdev)
+{
+       struct smmu_pmu *smmu_pmu = platform_get_drvdata(pdev);
+
+       smmu_pmu_disable(&smmu_pmu->pmu);
+}
+
+static struct platform_driver smmu_pmu_driver = {
+       .driver = {
+               .name = "arm-smmu-v3-pmcg",
+       },
+       .probe = smmu_pmu_probe,
+       .remove = smmu_pmu_remove,
+       .shutdown = smmu_pmu_shutdown,
+};
+
+static int __init arm_smmu_pmu_init(void)
+{
+       cpuhp_state_num = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
+                                                 "perf/arm/pmcg:online",
+                                                 NULL,
+                                                 smmu_pmu_offline_cpu);
+       if (cpuhp_state_num < 0)
+               return cpuhp_state_num;
+
+       return platform_driver_register(&smmu_pmu_driver);
+}
+module_init(arm_smmu_pmu_init);
+
+static void __exit arm_smmu_pmu_exit(void)
+{
+       platform_driver_unregister(&smmu_pmu_driver);
+       cpuhp_remove_multi_state(cpuhp_state_num);
+}
+
+module_exit(arm_smmu_pmu_exit);
+
+MODULE_DESCRIPTION("PMU driver for ARM SMMUv3 Performance Monitors Extension");
+MODULE_AUTHOR("Neil Leeder <nleeder@codeaurora.org>");
+MODULE_AUTHOR("Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>");
+MODULE_LICENSE("GPL v2");